Figure 14-46.—Track location on a 3/4-inch U-Matic videotape.
Audio Track
Virtually all formats of videotape provide at least
two distinct areas for the recording of audio information.
They are placed indifferent locations on the videotape
but perform the same as regular audiotape.
Control Track
The control track consists of electronic blips or
spikes, called sync pulses, recorded in precise intends
of one-thirtieth of a second. Since it provides the
necessary foundation for the editing process, you
cannot edit without a control track on your blank
(source) tape in the insert edit mode. The insert edit
mode is explained later.
Laying the control track on a blank videotape is the
first step in the videotape editing process in the insert
edit mode. Most television studios have a “black burst”
generator that produces a crystal black signal you may
record and use as a control track. You also can record a
control track from another tape — for example, a tape
that has color bars and tone.
Time Code Address Track
The time code address track is used to record cuing
information for editing. This information may consist of
audio or visual time/frame identification.
Figure 14-46 shows the location of all four tracks
on a 3/4-inch U-Matic videotape.
VIDEOTAPE EDITING PROCESS
Videotape editing is essentially a transfer process in
which a playback VCR, containing the recorded
segments, transfers its material onto an edit/record VCR
that assembles the various segments into a finished
form. The editing control unit (ECU) is equipped with
highly sophisticated electronic circuitry and allows the
operator to control exactly where the old material on the
edit/record VCR will end and the new material playing
in from the playback VCR will begin.
The precision of the edits depends largely on your
reaction time and skill. You must precue both
videocassette tapes accurately before the editing begins,
since you will control exactly where and when the edit
will occur while the two VCRs are rolling.
You will do your editing in what is called an editing
cell. Most NBS detachments have two or more editing
cells containing the following equipment:
l
l
l
l
l
l
Playback VCR
Edit/record VCR
Television monitor for the playback VCR
Television monitor for the edit/record VCR
Audio mixer
ECU
A typical editing cell is shown in figure 14-47.
EDITING MODES
On an editing cell, you may make either assemble
edits or insert edits. Both are explained in the following
text.
Assemble Edits
In the assemble editing mode, the ECU adds control
track and program footage (both audio tracks and the
video track) to the edit/record VCR at a predetermined
in-edit point. The edit/record VCR continues recording
the new information and the control track until it is
stopped. When you are assemble editing, you are
inserting a new control track at each in-edit point and
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